Our email is setup through Exchange on Small Business Server. We are having problems with sending email to some domains because our email domain we are using doesn't match the ip address we are sending the emails from. We are not hosting our email or domain.
Here is an example of our setup:
isp ip 100.100.100.100 (emails are sent from here)
myemaildomain.com ip 188.8.131.52
Here is the error we receive:
<myemaildomain.com #5.5.0 smtp;521-EHLO/HELO from sender ***.***.***.100 does not map to myemaildomain.com in DNS>
What config changes should I make in order to correct this problem?